This invention relates to programmable sequencer apparatus which has a multiplicity of uses. A specific and very important use for a programmable sequencer as disclosed in this application is the control of wash wheels in the laundry industry.
There exists in the United States today a substantial number of wash wheels being employed in commercial laundries which are programmably controlled by mechanical switches driven by a motor which interact with a nonconducting program chart having holes cut therethrough to determine the sequence of operations (or formula) required by the particular type of washing being done by the wash wheel under control. For example, the existing controls can set temperature of water, introduction of steam, introduction of chemicals and in addition, the time interval and sequence of each of the above.
The existing controls suffer from many disadvantages. First, the generation of program charts for the existing controls require from a half hour to forty-five minutes of a skilled operator's time. Further, if an error were made in the cutting of a program chart, in most instances the chart would have to be discarded completely and a new chart started from scratch. Further, if it is desired to change a program, the existing chart, in most instances, would be discarded and a new chart cut.
A further problem which exists with the current controls is the fact that the electrical contacts thereof are exposed to the air. It is not practical to seal these contacts since the program chart is physically placed between the operative contacts. Thus the advances in sealing of relay contacts which have occurred over the last twenty years or so cannot be used to advantage in the controls presently in the field. As a result of this exposure of the contacts, substantial corrosion occurs, particularly in the humid and corrosive environment of a commercial laundry. This results in downtime of the machinery and extensive repair costs.
A further problem which exists with the existing controls is the fact that skilled operators are required to align the program charts or else the machinery will not function properly.